Window sash balances



Sept. 13, 1966 P. sKoLNlK 3,271,312

WINDOW SASH BALANCES Filed March l5, 1964 2 Sheets-Shea?l 2 INVENTOR Pff/A Kom/K;

ATTORNEY United States Patent O 3,271,812 WINDOW SASH BALANCES Phil Skolnik, 13131 Almeda Road, I.0. Box 45558, Houston, Tex. Filed Mar. 13, 1964, Ser. No. 351,639 1t) Claims. (Cl. 16-197) This invention relates to improvements in window sash balances and, more particularly, to such balances of the spiral type.

Heretofore, the industry has provided window sash spiral balances to assist in lifting the sash and for holding the sash in its last operated position. Such balances usually comprise a fixed, elongated casing having a spiral rod mounted internally thereof for longitudinal movement, one end of the rod being connected t-o a window sash. A coil spring having a spring anchor on each end is associated with the spiral rod and the casing so that movement of the window sash, and consequential longitudinal movement of the spiral rod, torsionally loads the coil spring.

Although such spiral balances offer operational advantages over their structural alternatives, such balances are complicated and troublesome to assemble. Further, the means utilized for supporting a spring anchor in the casing in a longitudinally fixed but rotatable manner are not always -satisfactory because of maintenance requirements and a lack of structural integrity.

It is an object of this invention to provide a spiral balance for window sash that is uncomplicated and easy to assemble.

It is another object of this invention to provide a spiral balance wherein a longitudinally iixed but rotatably mounted spring anchor may be conveniently installed in the balance casing, but nevertheless, requires little maintenance and offers structural integrity.

It is also an object to provide a connection between a spring anchor and a spring that is operationally sound and yet permits ease in assembly.

It is still another object of this invention to provide a balance casing which permits ease in assembly of the other elements of the balance therein.

In achieving these objects, as well as others which will appear hereinafter, the present invention provides a spiral balance comprising an elongated casing having aperture means in one end thereof, a coil spring one end of which is iixed in another end of the casing, spring anchor means fixed to another end of said spring, a spiral rod associated with said spring anchor means so that longitudinal movement of said rod relative to said spring anchor means causes rotary movement of said spring anchor means, and bearing means inserted through said aperture means in said casing to restrain longitudinally but rotatably mount said spring anchor means.

The sash balance may further comprise a second spring anchor means, a portion of which is polygon-al in cross section and slidably received in the casing which may also be of the same cross section to restrain rotationally the anchor.

To facilitate installation of the spring on the spring anchors, either or both of these anchors may be provided with bored, frusto-conical spring receiving portions, the outside minor diameter of the frusto-conical portions being less than the inside diameter of the spring in a relaxed condition, but wherein the outside major diameter of the frusto-conical portions is appreciably greater than the relaxed inside diameter of the spring, whereby the spring may be conveniently slipped on the frusto-conical portions but thereafter the spring is rotationally retained on these portions by the tension induced in the spring.

This preferred embodiment of the invention is illustrated in the accompanying drawings in which:

3,271,812 Patented Sept. 13, 1966 ICC FIG. 1 is a front elevational view, partially in section, showing the :present sash balance fixed to a window frame and sash;

FIG. 2 is a top sectional view of the sash balance shown in FIG. 1, and taken along line 2-2 thereof, -showing the positioning of the balance in a sash channel;

FIG. 3 is a perspective view of the sash balance shown in FIG. l, a portion of the lower end thereof being broken away;

FIG. 4 is a top view of the upper spring anchor positioned in the casing as shown in FIG. 5;

FIG. 5 is a vertical7 cross sectional view of the upper spring anchor positioned within the casing of the sash balance shown in FIG. 1;

FIG. 6 is a vertical, cross sectional view of the lower spring anchor positioned in the casing of the sash balance shown in FIG. l but before the insertion of the bearing assembly therein;

FIG. 7 is a perspective view of the lower spring anchor shown in FIG. 6 along with the bearing assembly which supports the same in the casing; and

FIG. 8 is a bottom` view of the lower spring anchor shown in FIG. 5 retained in the casing by the bearing assembly and with the spiral rod shown in cross section.

Referring in lmore detail to FIG. l of the drawings, the present sash balance 2 is shown positioned in a conventional window frame. The window frame comprises a vertically extending jamb 4, a horizontally extending lintel 6 tixed to the upper end `of the jamb 4 and a horizontally extending sill 8 fixed to the lower end of the jamb. As shown in FIG. 2, the frame further comprises a vertically extending parting strip 10 and a vertically extending facing strip 12 both of which are iixed to the jamb 4- 4and between which a lower sash 14 is slidably mounted. The vertical lateral yface of the lower sash 14 is provided with a vertically extending channel 16 shown as `square in cross section to receive the spiral balance 2. Although but one spiral balance is shown in connection with the one lateral face of the lower sash, it will be appreciated that the present sash balance may be applied to one or both opposite sides :of both the top and bottom sashes in the usual manner.

The present spiral balance 2 comprises a vertically extending casing 18 which may be polygonal but preferably is square in cross section. The casing 18 may be enclosed on four sides but preferably, is provided with a vertically extending cutaway 20 along the full length of one side thereof, as shown in the lower portion of FIG. 3. As shown in FIG. 5, slidably but snugly received in the upper end of the casing 18 is an upper spring anchor 22, having a longitudinally extending bore 24 therethrough. The entire anchor 22 is preferably constructed of nylon or the like. The anchor 22 is provided with an upper portion 25 which is square in cross section and with rectangular shoulders 26 on two sides of the square upper portion 25. The outside dimension of the anchor 22 @from shoulder t-o shoulder is substantially equal to the inside dimension of the square casing 18. It will be seen that the anchor 22 may be slidably received in the casing 18 to the depth permitted by the shoulders 26 but retained in the casing against rotary movement. The upper portion 25 of the anchor 22 is further provided with -a laterally extending bore 30 which is positioned to cooperate with an aperture y3:2 on one side of the square casing 18 to receive any conventional connector such as a wood screw 33 or the like.

The upper spring anchor 22 is further provided with a tubular, frusto-conical portion 34 fixed to and subjacent the square upper portion 25. Fixedly positioned on the frusto-conical portion 34 is one end of a coil spring 36 of the llat wire type. The outside minor diameter of the lfrusto-conical portion 34 is approximately equal to the inside diameter lof the spring 34 in relaxed condition. However, the outside major diameter of the frusta-conical portion 34 is appreciably greater than the inside diameter of the spring 36 in a relaxed condition. t

In assemblying this device, because of the frusto-conical conguration, the lower end of the :anch-or 22 may be conveniently inserted internally of the spring 36, but upon forcing the portion of the truste-conical portion 34 having the major diameter into the spring, the spring is diametrically expanded to such a degree that it is rotatably secured to the frusto-conical portion 34 of the anchor 22 by the tension induced in the spring.

Referring to FIG. 6, the lower end of the coil spring 36 is xedly positioned on a lower spring anchor 40, also constructed of nylon or the like, and having a longitudinally extending bore 42 therein. The lower spring anchor 48 includes a tubular, frusto-conical portion 44 of similar dimensions to the frusto-conical portion 34 of the upper spring anchor 22 for receiving the lower end of the spring 36. The lower end of the spring anchor 40 includes two, spaced, annular shoulders 46 and 48 having therebetween a tubular portion 50 of a reduced diameter. Near the lower end of the bore 42 a pair of inwardly projecting, opposed, semi-circular shoulders 52 and 54 are provided, the space therebetween forming a rectangular slot 56.

To x longitudinally but rotatably mount the lower spring anchor 40 in the lower end of the casing 18, a pair of generally U-shaped, split bearing inserts 58 and 60 are provided, as shown in FIG. 7. The inserts 58 and 60 are also constructed of nylon or the like and are identical in shape. Each insert 58 and 68 comprises a at, horizontally extending, generally U-shaped portion 62, the dimension along a leg of the U being substantially equal to the outside dimension of the square casing 18. The width of each U-shaped insert 58, 60 is substantially equal to the inside dimension of the square casing 18. Each insert 58 and 60 further comprises a generally U-shaped block 64 of equal thickness as and fixed to the base of the U-shaped portion 62. Also, the width of each block 64 is substantially equal to the dimension between the legs of the U-shaped portion 62. To retain the inserts 58 and 60 in the casing 18, the at face of each U-shaped portion 62 is -provided with a pair of spaced, triangularshaped projections 68, removed `from the outside edge of the U-shaped portion 62 a distance slightly greater than the wall thickness of the casing 18.

To permit installation of the insert 60 in the casing 18, a rectangular aperture 70, as shown in FIG. 3, is provided in one side of the lower end of the casing. The length and width of the aperture 70 are only slightly greater than the width and thickness, respectively, of the insert 68. Similarly, to permit installation of the insert 58 in the casing 18, a rectangular notch 72 is provided on each side, and near the lower end, of the vertically extending cutaway 20 of the casing 18.

For installing the inserts 58 and 60 in the casing 18, the inserts are oriented, in relation to each other, as shown in FIG. 7. Upon inserting the inserts in the casing 18 through the aperture 70 and the notches 72, it will be seen that the insert 58 is superposed on the insert 60 and the two inserts together form a genera-lly fiat, composite bearing assembly spanning the casing 18 and having a circular bore 74 through the center thereof for reception of the tubular portion 50 of the spring anchor 40. The annular shoulders 46 and 48 of the anchor 40 abut the upper and lower faces of the inserts 58 and 60, respectively, to longitudinally retain the spring anchor 40 within the housing 18, but to rotatably mount the same. The triangular-shaped projections 68 on the flat faces of the inserts 58 and 68 are not so large as to hinder insertion of the inserts but nevertheless 4function to retain the inserts within the interior of the housing 18.

Referring to FIG. 1, positioned internally of the spring 36 in the casing 18 is an elongated spiral rod '75 having an upper llattened end 76 with a stop 77 integral therewith. The rod is positioned in the slot 56 of the lower spring anchor 40 and lower end of the spiral rod 75 is also provided with a attened portion 78 having a longitudinally extending, rectangular slot 80 for reception of a cross member 82. Projecting from the lower end of the cross member 82 is a pair of detents 84 having a space therebetween so 'that the cross member 82 may be slidably inserted in the slot 80, and after the center of the cross member 82 is positioned in the slot 80, the cross member may be pressed downwardly to -position one detent 84 on either side of the attened portion 78 to laterally retain the cross member 82 in the slot 8).

A suitable bracket 86 is secured in any convenient manner on the underside of the sash 14 to attach the spiral rod 75 to the sash 14, by embracing the cross member 82.

Assembling the present spiral balance is a simple procedure. It is merely necessary to insert the upper and lower spiral anchors 22 and 48 in opposite ends of the spring 36 in a forcible manner so as to tix rotationally the spring on the frusto-conical portions of each anchor. The spring with the anchors attached is then inserted through the upper end of the casing 18 until the shoulder portions 26 of the upper anchor 22 abuts the upper end of the casing. The spiral rod 75 is then dropped through the bore 24 of the upper anchor assembly Z2, the lower end 78 of the rod passing through the rectangular slot 56 in the lower anchor 40. The bearing inserts 58 and 60 are then inserted through opposite sides of the casing 18 so as to embrace the tubular portion 56 and longitudinally restrain but rotatably mount the lower anchor 40 in the casing 18. Subsequently, the cross member 82 is inserted in the slot 88 of the spiral rod 7S and pressed downwardly therein.

As Shown in FIG. l, the screw 33 may `be utilized to secure the spiral balance 2 to the vertically extending jamb 4 of the window frame, and the bracket 86 may be mounted to embrace the cross member 82 to connect the spiral rod to the lower sash 14.

In operation, the spiral balance acts to hold the window sash in its last operated position and to assist in lifting the sash. The function is achieved by connecting the lower end 78 of the spiral rod 75 to the window sash 14 when the sash is in a fully raised condition and the spring 36 is under minimum torsional stress. Upon lowering the window, the spiral rod 75 is carried downwardly and as the spiral rrod is moved through the rectangular slot 56, the spring anchor 40 is rotated to thereby increase the torsional load on the spring 36. If downward movement of the wind-ow sash is interrupted at any point, the torsional load on the spring 36 acts to ofset the weight of the window tending to urge the Window further `down. When the window sash is in the fully lowered position, and the spring 36 is fully loaded, raising of the window sash is aided 4by the torsional load on the spring which acts to urge the window sash in an upward direction.

From the above, it will be seen that the present spiral balance offers significant advantages in simplicity in construction, structural integrity, and ease of assembly.

While the invention has been illustrated and described l a coil spring one end of which is lixed in another end of said casing, spring anchor means in said aperture means transverse to said longitudinal axis of said casing, said bearing means longitudinally restraining but rotatably mounting said spring anchor means.

2. A sash balance for use with a window sash, said balance comprising an elongated casing having aperture means in one end thereof, a coil spring one end of which is fixed in another end of said casing, spring anchor means fixed to another end of said spring, a spiral rod, means operatively associating said spiral rod With said spring anchor means so that longitudinal movement of said spiral rod relative to said spring anchor means causes rotary movement of said spring anchor means, bearing means supported in said aperture means in said casing to longitudinally restrain but rotatably mount said spring anchor means, said bearing means comprising a plurality of superposed, U-shaped inserts.

3. A sash balance for use with a window frame ac- -cording to claim 2 wherein the length of each of said inserts is substantially equal to the Width of said casing.

4. A sash balance for use with a window sash according to claim 2 wherein means are provided integral with said inserts to retain said inserts in said casing.

5. A sash balance for use with a window sash according to claim 2 wherein said bearing means is constructed of nylon.

6. A sash balance for use with a window sash according to claim 1, said spring anchor means including a frusto-conical portion xedly receiving one end of said coil spring.

7. A sash balance for use with a window sash laccording to claim 1 wherein said casing is rectangular in cross section and said one end of said spring is iiXed in said another end of said casing by second spring anchor means which includes a rectangular portion slidably but rotatably fixed in said casing.

8. A sash balance for use with a window sash according to claim 1 wherein said anchor means and said bearing means are constructed of nylon.

9. A sash balance for use with a window sash, said balance comprising an elongated casing having an aperture means in one end thereof, an elongated coil spring positioned in said casing, rst and second spring anchor means, each of said anchor means including a frustoconical portion iixedly receiving opposite ends of said coil spring, bea-ring means comprising a plurality of superposed, U-shaped inserts supported in said aperture means and spanning said casing to longitudinally restrain but rotatably mount said second spring anchor means, a

spiral rod, means operatively connecting said spiral rod with said second spring anchor means so that longitudinal movement of said spiral rod relative to said second spring anchor means causes rotary movement of said second spring .anchor means.

10. A sash balance for use with a window sash, said balance comprising a rect-angular, elongated casing having aperture means in one end thereof, an elongated coil spring positioned in said casing, a rst spring anchor means positioned in an opposite end of said casing, said anchor means having a bore .through the length thereof and including la rectangular portion substantially equal4 in size to the interior dimensions of said casing, the upper end of said rectangular portion having rectangular shoulders projecting over the top of said opposite end of said casing, said rst spring anchor having a frustoconical portion fixed subjacent said rectangular portion for iixedly receiving one end of said coil spring, a sec- -ond spring anchor means positioned in said one end of .said casing and having a bore through the length thereof, said second spring anchor means including spaced, circular shoulders and a frusto-conical portion for iixedly receiving an opposite end of said coil spring, bearing means supported in said aperture means and spanning said casing, said bearing means comprising a plurali-ty of superposed U-shaped inserts, each insert being of a length substantially equal to the Width of said casing and including means integral therewith to retain the same in said casing, said bearing means positioned Ibetween said shoulders on said second anchor means for longitudinally restraining but rotatably mounting said second spring anchor means in said casing, an elongated spiral rod, means operatively connecting said spiral rod with said second spring anchor means so that longitudinal movement of said spiral rod causes rotary movement of said second spring anchor means and thereby torsionally loads said coil spring.

References Cited by the Examiner UNITED STATES PATENTS 889,064 5/ 1908 Taylor 16-197 2,477,069 7/1949 Larson 16-197 2,851,721 9/1958 Decker et al 16-197 2,929,095 3/ 1960 Nobes 16-197 EDWARD C. ALLEN, Primary Examiner'.

I. H. MCGLYNN, Assistant Examiner. JOSEPH D. SEERS, Examiner. 

1. A SASH BALANCE FOR USE WITH A WINDOW SASH, SAID BALANCE COMPRISING AN ELONGATED CASING HAVING A LONGITUDINAL AXIS AND INCLUDING APERTURE MEANS IN ONE END THEREOF, SAID APERTURE MEANS HAVING AN AXIS TRANSVERSE TO SAID LONGITUDINAL AXIS, A COIL SPRING ONE END OF WHICH IS FIXED IN ANOTHER END OF SAID CASING, SPRING ANCHOR MEANS FIXED TO ANOTHER END OF SAID SPRING A SPIRAL ROD, MEANS OPERATIVELY ASSOCIATING SAID SPIRAL ROD WITH SAID SPRING ANCHOR MEANS SO THAT LONGITUDINAL MOVEMENT OF SAID ROD RELATIVE TO SAID SPRING ANCHOR MEANS CAUSES ROTARY MOVEMENT OF SAID SPRING ANCHOR MEANS, AND BEARING MEANS IN SAID APERTURE MEANS TRANSVERSE TO SAID LONGITUDINAL AXIS OF SAID CASING, SAID BEARING MEANS LONGITUDINALLY RESTRAINING BUT ROTATABLY MOUNTING SAID SPRING ANCHOR MEANS. 